package thread;

class Test {
    public int count = 0;
    public void add() {
        synchronized (Test.class) {//写成Test.class 类对象,每个类都有一个类对象,里面包含这个类的各种信息,这个是反射机制的依据
            count++;//理解好this是不是同一个对象,因为是同一个类对象,所以锁竞争任然存在
        }
    }
}
public class ThreadDemo20 {
    public static void main(String[] args) throws InterruptedException {
        Test t = new Test();
        Thread t1 = new Thread(() ->{
            for(int i = 0; i < 50000; i++ ) {
                t.add();
            }
        });

        Thread t2 = new Thread(() ->{
            for(int i = 0; i < 50000; i++ ) {
                t.add();
            }
        });
        t1.start();
        t2.start();

        t1.join();
        t2.join();
        System.out.println("count = " + t.count );

    }
}
